(1) Field of the Invention
This invention relates to fire extinguishers.
(2) Description of the Related Art
There are a wide variety of fire extinguishing technologies and fire extinguisher constructions. These include propellant-actuated extinguishers and extinguishers charged with compressed and/or liquefied gas. United States Military Specification MIL-E-52031D(ME)(5 Sep. 1979), the disclosure of which is incorporated by reference herein in its entirety, identifies a hand-held and actuated vaporizing-liquid fire extinguisher. This exemplary extinguisher utilizes CF3Br (monobromotrifluoromethane) suppressant.
U.S. Pat. No. 3,228,474 of Huthsing, Jr. discloses a portable extinguisher operated by puncturing a gas cartridge to pressurize the extinguisher.
The basic features of an early propellant-actuated extinguisher are seen in U.S. Pat. No. 2,530,633 (Scholz). Scholz discloses a fire extinguisher wherein xe2x80x9ca liquid extinguishing medium, such as methyl bromide, is expelled from its container by gas evolved from the burning ofxe2x80x9d a pyrotechnic charge. The charge is originally stored in a container, which includes electric squibs. The charge container is mounted in an upper end of the vessel within a xe2x80x9ccontainer cupxe2x80x9d. Opposite the container cup, an outlet from the vessel is formed by an elbow fitting sealed by a rupturable diaphragm. Ignition of the pyrotechnic charge ruptures a lower wall of the charge container and vents combustion gases into the vessel. The combustion gases serve xe2x80x9cas a gas piston acting on the surface of the liquidxe2x80x9d rupturing the diaphragm which sealed the outlet and propelling the liquid out of the extinguisher.
The application of a propellant-actuated extinguisher to use in military vehicles is described in U.S. Pat. No. 4,319,640 (Brobeil). Brobeil discloses an extinguisher in many ways similar to Scholz. The exemplary fire suppressant utilized is Halon 1301. The lower end of the extinguisher vessel is sealed by a rupturable diaphragm. A gas generating device is mounted atop the neck of the vessel. The exemplary gas generating composition is 62% sodium azide and 38% copper oxide.
Patent Cooperation Treaty International Application PCT/US00/05953 (published as WO 00/57959) discloses a hybrid fire extinguisher.
Patent Cooperation Treaty International Application PCT/US00/30726 (published as WO 01/34516), the disclosure of which is incorporated by reference in its entirety herein, discloses a number of gas generation systems.
One area of the invention involves the remanufacturing of a fire extinguisher. Advantageously, the remanufacturing may involve the conversion of a vaporizing-liquid extinguisher (preferably an expended one) to a propellant-actuated extinguisher. The cylinder or bottle is preferably reused as is the major portion of the discharge assembly. There may, advantageously, be a degree or cleaning or reconditioning of any reused components and assemblies. To the reused discharge assembly portion, there is added a portion including an elongate flexible gas generating component and means for igniting the component. The elongate flexible nature of the generator is advantageous to permit it to be inserted through the typically narrow opening in the bottle. Advantageously, the reused portion of the discharge assembly includes a lance previously utilized to puncture a seal to initiate discharge and, in the remanufactured condition, puncturing a seal and also actuating a firing pin to trigger a primer as the igniting means.
Other aspects of the invention involve the resulting fire extinguisher as well as fire extinguishers sharing construction details and operating parameters but not necessarily having been remanufactured from the previous conditions. In preferred implementations, the suppressant consists essentially or in major part of heptafluoropropane or a similar agent. The combustion gasses from the gas generator provide pressure and heat and diffuse into the suppressant and discharge the suppressant from the extinguisher. This combination may make the suppressant perform more similarly to a halon system than if the suppressant were merely squirted out under a cold supercharged mode (e.g., as if driven by a piston).
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.